A patient is prescribed Flexeril (cyclobenzaprine) for muscle spasms. Which of the following is the most common side effect that the nurse should educate the patient about?

Choice A reason: Increased respiratory rate is not a sign of adverse reaction to metoprolol, but rather a normal response to hypoxia or distress. Metoprolol is a betablocker that can lower the heart rate and blood pressure, but it does not affect the respiratory rate directly.

Choice B reason: Bronchodilation is not a sign of adverse reaction to metoprolol, but rather a desired effect of asthma medications such as betaagonists or anticholinergics. Metoprolol is a betablocker that can block the beta receptors in the lungs, which can cause bronchoconstriction or narrowing of the airways. This is why metoprolol is contraindicated or used with caution in clients with asthma.

Choice C reason: Decreased sputum production is not a sign of adverse reaction to metoprolol, but rather a result of effective asthma management. Metoprolol is a betablocker that does not have any direct effect on the mucus secretion or inflammation in the lungs.

Choice D reason: Wheezing is a sign of adverse reaction to metoprolol, as it indicates bronchoconstriction or narrowing of the airways. Metoprolol is a betablocker that can block the beta receptors in the lungs, which can reduce the bronchodilation effect of beta agonists or other asthma medications. This can worsen the asthma symptoms and cause wheezing, coughing, dyspnea, or chest tightness. The nurse should monitor the client for these signs and report them to the prescriber immediately.

Choice A reason: The initial phase of drug distribution is not the correct definition of the term 'first pass effect'. Drug distribution is the process by which a drug moves from the bloodstream to the tissues and organs of the body. The initial phase of drug distribution is influenced by factors such as blood flow, tissue permeability, plasma protein binding, and tissue binding. The first pass effect is not related to drug distribution, but to drug metabolism, which is the chemical transformation of a drug in the body.

Choice B reason: The rapid absorption of a drug in the intestine is not the correct definition of the term 'first pass effect'. Drug absorption is the process by which a drug enters the bloodstream from the site of administration. The rapid absorption of a drug in the intestine depends on factors such as the drug formulation, the pH of the gastrointestinal tract, the presence of food or other drugs, and the surface area and motility of the intestine. The first pass effect is not related to drug absorption, but to drug metabolism, which is the chemical transformation of a drug in the body.

Choice C reason: The initial rapid excretion of a drug through the urinary system is not the correct definition of the term 'first pass effect'. Drug excretion is the process by which a drug or its metabolites are eliminated from the body. The initial rapid excretion of a drug through the urinary system is influenced by factors such as the renal blood flow, the glomerular filtration rate, the tubular secretion and reabsorption, and the urine pH. The first pass effect is not related to drug excretion, but to drug metabolism, which is the chemical transformation of a drug in the body.

Choice D reason: The metabolism of a drug before it reaches the systemic circulation is the correct definition of the term 'first pass effect'. Drug metabolism is the process by which a drug is chemically transformed in the body, usually by enzymes in the liver or other tissues. The first pass effect is a phenomenon of drug metabolism that occurs when a drug is administered orally and passes through the gastrointestinal tract and the liver before reaching the systemic circulation. The first pass effect can reduce the bioavailability and the effectiveness of the drug, as some or most of the drug may be metabolized and inactivated before reaching the site of action.